(7+d)*(d-7)+(d+3)*(3-d)+40*(d+1)при d=0.5

Question

(7+d)*(d-7)+(d+3)*(3-d)+40*(d+1)при d=0.5

Answer 1

(7 + d)(d - 7) + (d + 3)(3 - d) + 40(d + 1) = (d + 7)(d - 7) + (3 + d)(3 - d) +
+ 40(d + 1) = d² - 49 + 9 - d² + 40d + 40 = 40d
Если d = 0,5 , то 40 * 0,5 = 20