Найдите значение выражения:
а)
при a = 6,6, b = 0,4:
при x = 0,5, y = 2,5:
при a = 4, x = −3:
при x = 2, b = 12,5, c = 8,3:
xb − xc + 3c − 3b = (xb − xc) − (3b − 3c) = x(b − c) − 3(b − c) = (b − c)(x − 3) = (12,5 − 8,3)(2 − 3) = 4,2 * (−1) = −4,2
при a = −2, x = 9,1, y = −6,4:
ay − ax − 2x + 2y = (ay − ax) + (2y − 2x) = a(y − x) + (y − x) = (y − x)(a + 2) = (−6,4 − 9,1)(−2 + 2) = −15,5 * 0 = 0
при a = 3, b = −13, x = −1, y = −2:
3ax − 4by − 4ay + 3bx = (3ax + 3bx) − (4ay + 4by) = 3x(a + b) − 4y(a + b) = (a + b)(3x − 4y) = (3 − 13)(3 * (−1) − 4 * (−2)) = −10 * (−3 + 8) = −10 * 5 = −50