(d-10)в квадрате +(4-d)(d+4)=0

Question

(d-10)в квадрате +(4-d)(d+4)=0

Answer 1

(d-10)²+(4-d)(d+4)=0
d²-20d+100+(4²-d²) =0
d²-20d+100+16-d²=0
-20d+116=0
-20d=-116
d= 116:20 =5.8