Go Math 8.1: Solutions of Equations

Go Math 8.1: Solutions of Equations

(p. 421-426)

What is an Equation?

.

What is a solution?

.

Fill in the Blank

Substitute 14 for w in w + 5 = 29

Fill in the Blank

Add 14 + 5 so that the equation reads as ____ = 29

Multiple Choice

Does 19 = 29

• Yes

• No

• Sometimes

• Maybe

The equation is not true when w=14, so w=14 is not a solution.

A number is a solution when you plug it in and both sides are equal.

Determine whether the given value (number) of a variable is a solution to each equation.

1) Write the equation.

2) Replace the variable with the number given.

3) Perform the operations and see if the two sides are equal or not.

Multiple Choice

x - 0.7 = 4.3 for x = 3.6

That means plug in 3.6 for x

What do you get?

• 10.8 = 4.3

• 5.2 = 4.3

• 4.3 = 4.3

• 2.9 = 4.3

Multiple Choice

Since we get 2.9 = 4.3

and 2.9 does not equal 4.3

The 3.6 we plugged in ______ a solution.

• is

• is not

• yes

• 15

Multiple Choice

m + 2.5 = 4.6; m = 2.9

When I plug in 2.9 for m, I get:

• 5.4 = 4.6

• 8.2 = 4.6

• 4.6 = 4.6

• 3.7 = 4.6

Multiple Choice

When we plug in 2.9 for m in the equation m + 2.5 = 4.6

we get 5.4 = 4.6

Since 5.4 does not equal 4.6, we say that plugging in 2.9 for m ____ a solution to the equation.

• is

• is not

• always

• 6

Multiple Choice

d - 8.7 = 6; d = 14.7

Plug in 14.7 for d

That looks like 14.7 - 8.7 = 6

When I find 14.7 - 8.7, I get:

• 6 = 6

• 2.2 = 6

• 8 = 6

• 9.5 = 6

Multiple Choice

So d = 14.7 _____ a solution for d - 8.7 = 6

• is

• is not

• 33

• equivalent

Multiple Choice

17.9 + v = 35.8; v = 17.9

When I plug in 17.9 for v, I get

• 16.6 = 17.9

• 26.4 = 35.8

• 33 = 17.9

• 35.8 = 35.8

Multiple Choice

Remember, if you get the same number on both sides, the number you plugged in IS a solution.

If you get different numbers on both sides of the equals sign, the number you plugged in IS NOT a solution of the equation.

So, in the problem you just worked on, 17.9 _____ a solution.

• is

• is not

• sometimes

• 6

Multiple Choice

c + 35 = 57; c = 32

When I plug in 32 for c, I get

• 57 = 57

• 67 = 57

• 53 = 67

• 44 = 67

Multiple Choice

Remember, if you get the same number on both sides, the number you plugged in IS a solution.

If you get different numbers on both sides of the equals sign, the number you plugged in IS NOT a solution of the equation.

So, in the problem you just worked on, 32 _____ a solution.

• is

• is not

• sometimes

• 6

Multiple Choice

18 = (2/3)h; h = 12

When I replace h with 12, I get:

So h = 12 ______ a solution.

• 18 = 8

  
  

  is not

• 18 = 18

  
  

  is

• 18 = 12

  
  

  is not

• 18 = 21

  
  

  is not

Multiple Choice

In the equation t + 2.5 = 7, determine whether t = 4.5, t = 5, or t = 5.5 is a solution to the equation.

• t = 4.5

• t = 5

• t = 5.5

Multiple Choice

The marking period is 45 school days long. Today is the twenty-first day of the marking period. The equation x + 21 = 45 can be used to find the number of days left in the marking period. Using substitution, how many days are in the marking period?

• 20

• 24

• 26

• 32