(4х)²+2*4х*5+5²=(4х)²-2*4х*7+7²

16х²+40х+25=16х²-56х+49

16х²+40х+25-16х²+56х-49=0

96х-24=0

96х=24

х=0,25

16x^2+40x+25=16x^2-56x+49

16x^2+40x+25-16x^2+56x-49=0

96x-24=0

x=0.25