Répondre :
1) (7+3x)²+(8-x)²
49+42x+9x²+64-16x+x²
10x²+26x+113
2) x=1
(7+3x1)²+(8-1)²
(10)²+(7)²=100+49=149
49+42x+9x²+64-16x+x²
10x²+26x+113
2) x=1
(7+3x1)²+(8-1)²
(10)²+(7)²=100+49=149