7a2 + 53a + 28 = 7a2 + 49a + 4a + 28 = 7a(a + 7) +4(a + 7) = (a + 7)(7a + 4)
59
28
basically you asked what -28+21 which equals -7
14 + 14 = 28
10
22+22+28+28=100.
it equals 28
it is 28
3x + 7 = -4x + 28 implies 7x + 7 = 28
59
That equals 28
25 + 28 + 29 = 82
58
22
28 + 42 = 70
19
18 + 10 + 28 + 10 = 66