Question

What is the value of (a+b) in the system of equations below?

6(a + b) + 2z = -8
a+b+z = 2
Selett one:
A. 3
O B.-4
O C. - 3
O D.-1

Answer 1

C

Explanation:

6(a+b) + 2z = -8 ; divide by 2

3(a+b) + z = -4

a+b+z = 2; subtract z from both sides

a+b = 2-z; substitute a+b into equation 3(a+b) +z = -4

3(2-z) +z = -4; distribute

6 - 3z+ z= -4 ; subtract 6 on both sides

-3z + z = -4 -6 ; combine like terms

-2z = -10; divide both sides by -2

z= 5

3(a+b) +z = -4; substitute z by 5

3(a+b) +5 = -4; subtract 5 from both sides

3( a+b) = -4 -5; combine like terms

3(a+b) = -9; divide both sides by 3

(a+b) = -3