计算:(1)(2).
(1); (2)
阅读理解,我们把称作二阶行列式,规定它的运算法则为=ad-bc,如=2×5-4×3=-2(1)计算(2)如果=-4,求y的值
计算2sin60°-tan60°-3tan30°+ ()+(-1)
计算: (1)1+2.25+(+3.625)+(-2)+(-1.4)+(-3); (2)(- +0.75- )×(-36); (3)[-×(- )+(- )÷]÷(-2)3; (4)-12015-[-3×(2÷3)2+22]- ; (5)x2y-3xy2+2yx2-xy2; (6)5a2-[3a-2(a-3)+4a2].
计算 (1) (2) (3) (4)