Question 1024038
A = one number
B = other number
A = -4 + 2B
A - B = 21
solve for A by adding B to each side
A = B + 21
Substitute (B + 21) for A in A = -4 + 2B
(B + 21) = -4 + 2B
add -B to each side
21 = -4 + B
add 4 to each side
25 = B
Since A = B + 21 , A = 25 + 21 , A = 46