Question

{(3x+5)+(x+2)} power 2+{(3x+5)-(x+2)} power 2=20xpower2-78​

Answer 1

Step-by-step explanation:

{(3x+5)+(x+2)}²+{(3x+5)-(x+2)}²=20x²-78

(3x+5+x+2)²+(3x+5-x-2)²=20x²-78

(4x+7)²+(2x+3)²=20x²-78

16x²+49+56x+4x²+9+12x=20x²-78

20x²+68x+58=20x²-78

20x²-20x²+68x=-78-58

68x=136

x=136/68

x=2