Sagot :
G= 5t x 2t + 5t x (-7) + 8 x 2t + 8 x (-7)
= 10t + (-35t) + 16t + (-56)
=26t - 35t -56
= -9t -56
= 10t + (-35t) + 16t + (-56)
=26t - 35t -56
= -9t -56
Explications étape par étape:
5t+8= 13t
2t-7= -5t
13t×(-5t) = -65t2