Remove all the brackets
3(7 + 2x) + 3 = 3(5 + x) − 9(x + 1)
21 + 6x + 3 = 15 + 3x - 9x - 9 Collect like terms.
24 + 6x = 6 - 6x Add 6x to both sides.
24 + 6x + 6x = 6 Subtract 24 from both sides
12x = 6 - 24
12x = - 18 Divide by 12
x = - 18 /12
x = - 1.5
Check
3(7 + 2*(-1.5)) + 3 = ? 3(5 + -(1.5) - 9(-1.5 + 1)
3(7 - 3) + 3 =? 3(3.5) - 9*(-1/2)
3*4 + 3 =? 10.5 + 4.5
12 + 3 =? 15 And it checks.
C and D
the volume ( V) of a pyramid is found using the formula
V = 
× area of base × height
calculating each of the volumes gives
(A) V = × 10.5 × 6 = 21 in³
(B) V = × 3.6 × 8 = 9.6 in³
(C) V = × 4.2 × 12 = 16,8 in³
(D) V = × 6 × 8.4 = 16.8 in³
C and D have equal volumes
Absolute value is the answer to this question!
