Question

If x2 - y2 = 12 and x - y = 4, what is the value
of x2 + 2xy + y?
F. 3
G. 8
H. 9
J. 12
K. 16

Answer 1

Step-by-step explanation:

x²-y²=12

(x-y)(x+y)=12

but x-y=4

4(x+y)=12

x+y=12/4

x+y=3

lets make x the subject of the formula

x=3-y

since x-y=4

(3-y)-y=4

3-y-y=4

-2y=1

y=-1/2

then x=3-y

x=3-(-1/2)

x=(6--1)/2

x=7/2

therefore; x²+2xy+y

=(7/2)²+2×7/2×-1/2+(-1/2)

=49/4-7/2-1/2

=(49-14-2)/4

=33/4

=8.25

=8