Question

(x+3)(x+7)-(x+4)^2=0
(y+8)^2-(y+9)(y-5)=117

Answer 1

1)(x+3)(x+7)-(x+4)^2=0
x^2+7x+3x+21-x^2-8x-16=0
2x+5=0
x= -2.5
Ответ:х= -2.5
2)(y+8)^2-(y+9)(y-5)=117
y^2+16y+64-y^2+5y-9y+45-117=0
12y-8=0
y= 2/3
Ответ:у=2/3

Answer 2

$1)(x+3)(x+7)-(x+4) ^{2} =0 \\ x^{2} +3x+7x+21- (x^{2} +16+8x)=0\\ x^{2} +10x+21- x^{2} -16-8x=0 \\ 2x+5=0 \\ 2x=-5 \\ x=- \frac{5}{2} \\ x=-2.5$

$2)(y+8) ^{2} -(y+9)(y-5)=117\\y ^{2} +64+16y-(y ^{2} -5y+9y-45)=117 \\ y ^{2} +64+16y-(y ^{2} +4y-45)=117\\y ^{2} +64+16y-y ^{2} -4y+45=117\\16y-4y=117-64-45\\12y=8 \\ y= \frac{8}{12} \\ y= \frac{2}{3}$