Solving an Equation with Substitution

3 = c -1

• 3

• 4

• -3

• 2

4.4 = x - 5.6

• 10

• 1.2

• 9.2

• 11

What method would you use to solve the following system of equations?

• solve for y

• Substitution, because there is an equation with an isolated variable

• Elimination with addition

• Elimination with multiplication

• elimination with subtraction

4g = 24

g = ?

• g = 96

• g = 28

• g = 6

• g = 20

Given the following systems of equations, what is the value of y?
y = 2x + 1
y = 4x - 1
Make sure you type your answer as y=

Mathematical Equivalence

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Find the value of (x, y) that satisfies the equations by solving the system using substitution.
 
5x + 4y= −14
y =  −7x  −  15  The solution is (a)   .

• (-2, -1)

• (0, 0)

• (1, 1)

• (2, 2)

If x+y=14 and x-y=4 then the values of x and y are_________

• x=4 and y = 5

• x = 9 and y = 7

• x = -6 and y = 5

• x = 9 and y = 5

Which of the following represents the correct equation when you substitute y into the equation?

Why does substitution help us solve a system of equations?

• It changes one variable to an expression using the other variable, so we can solve an equation that only has one variable at a time.

• It creates a problem with fewer steps.

• It puts both equations in slope-intercept form for easy graphing.