( 2a + 3 ) - ( 4a - 8 ) = 7
2a + 3 - 4a + 8 = 7
-2a + 11 = 7
-2a = -4
a = -4 / -2
a = 2
2(4+39) = 39 + 4 = 43
43 x 2 = 86
Part A: Coefficients: 20,5.
Variables: c,w
Constants:95.50
Length + width = 25cm
length = 25cm - width
length x width = 150 cm^2
(25cm-w)w= 150
25w-w^2=150
0=w^2-25w+150
0=(w-15)(w-10)
w=10cm
l=15cm
D would most likely be the answer.