Finding the value of an expression | Algebraic Expressions | Assessment | English | Grade 7

If a = 1, then the value of a² - 3a + 5 is equal to _____.

• -3

• 3

• 4

• 9

Answer explanation

Here a = 1 Let's put the value of a in expression a² -3a + 5 a² -3a + 5 = (1)² -3(1) + 5 = 1 - 3 + 5 = 6 - 3 = 3

Tags

CCSS.6.EE.A.2C

If x = 2 and y = 1, then the value of 5y² + 7xy + 2x² is equal to ______.

• 27

• 144

• 36

• 14

Answer explanation

Here x = 2 and y = 1 5y² + 7xy + 2x² = 5(1)² + 7(1)(2) + 2(2)² = 5 + 14 + 2(4) = 5 + 14 + 8 = 27

Tags

CCSS.6.EE.A.2C

Rhea has x chocolates. Shivani has 10 chocolates more than thrice the chocolates Rhea has. If x = 5, then find the total number of chocolates with Rhea and Shivani.

• 45

• 55

• 30

• 19

Answer explanation

Rhea has x chocolates Shivani has 10 more chocolates than 3 times of Rhea i.e. 3x + 10 To find the total number of chocolates, let's find the sum of x and 3x + 10 x + 3x + 10 = 4x + 10 Here x = 5 Therefore, 4x + 10 = 4(5) + 10 = 20 + 10 = 30 Therefore, there are total 30 chocolates

Tags

CCSS.6.EE.B.6

If p = 1, q = 2 and r = -1, then the value of p³q³ + q³r³ - r³p³ is equal to _____.

• 16

• 17

• 1

• -1

Answer explanation

Here p = 1, q = 2 and r = -1, therefore, p³q³ + q³r³ - r³p³ = (1)³(2)³ + (2)³(-1)³ - (-1)³(1)³ = (1)(8) + (8)(-1) - (-1)(1) = 8 - 8 + 1 = 1

Tags

CCSS.6.EE.A.2C

If x = -1 and y = 3, what will be the result if we subtract 2x² - 3 from 4x² + 2xy + 15?

• 26

• -14

• 32

• 14

Answer explanation

Given: x = -1 and y = 3 To find: (4x² + 2xy + 15) - (2x² - 3) (4x² + 2xy + 15) - (2x² - 3) = 4x² + 2xy + 15 - 2x² + 3 = 2x² + 2xy + 18 = 2 (-1)² + 2(-1)(3) + 18 = 2(1) - 6 + 18 = 2 - 6 + 18 = 20 - 6 = 14

Tags

CCSS.6.EE.A.2C

If P = 5x² + 2xy, Q = 3x² - xy + 10 and R = -4xy + 3, then what is the value of P + Q - R at x = 1 and y = -2?

• 5

• 11

• 31

• 8x² + 5xy + 7

Answer explanation

Let us first obtain the expression for P + Q - R P + Q - R = (5x² + 2xy) + (3x² - xy + 10) - (-4xy + 3) = 5x² + 2xy + 3x² - xy + 10 + 4xy - 3 = 5x² + 3x² + 2xy - xy + 4xy + 10 - 3 = 8x² + 6xy - xy + 7 = 8x² + 5xy + 7 Let's substitute the value of x = 1 and y = -2 in the expression. 8x² + 5xy + 7 = 8(1)² + 5(1)(-2) + 7 = 8 - 10 + 7 = 15 - 10 = 5

Tags

CCSS.6.EE.A.2C