7x - 44 = 4x + 4
Add both sides 44
7x - 44 + 44 = 4x + 4 + 44
7x = 4x + 48
Subtract both sides 4x
7x - 4x = 4x - 4x + 48
3x = 48
Divide both sides by 3
3x ÷ 3 = 48 ÷ 3
x = 16
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Suppose that the angle between 39 and 4x + 4 is t degrees as you know they make a straight line together thus :
39 + t + 4x + 4 = 180
39 + t + 4(16) + 4 = 180
39 + t + 64 + 4 = 180
39 + t + 68 = 180
t + 107 = 180
Subtract both sides 107
t + 107 - 107 = 180 - 107
t = 73
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8y - 43 = 4x + 4 + t
8y - 43 = 4(16) + 4 + 73
8y - 43 = 64 + 4 + 73
8y - 43 = 68 + 73
8y - 43 = 141
Add both sides 43
8y - 43 + 43 = 141 + 43
8y = 184
Divide both sides by 8
8y ÷ 8 = 184 ÷ 8
y = 23
