1)oblicz wartość wyrażenia dla x=-3/4 i y=-1/3 a)12x 2(potęga)y-7xy b)3x2(potęga) c)4xy+2x2(potęga)-3y2(potęga) d) -1/2(xy2(potęga)   2)Wykonaj działania: a) 5 17/24-(-2 3/8) b) (5 4/15-3 7/24):0,8 Daje naj. pozdrawiam

1. A) 12x^2y - 7xy = 12*(-3/4)^2*(-1/3)-7*(-3/4)*(-1/3)= 12*(9/16)*(-1/3) - 7 * (-3/4)* (-1/3) = 12 * (-9/48) - 7 *(3/12)= -108/48 - 21/12 = -108/48 - 88/48 = -196/48 = - 4 1/12   B) 3x^2= 3 * 9/16 = 27/16 = 1 11/16   C)4xy+2x^2-3y^2=  4 * (-3/4) * (-1/3) + 2*(-3/4)^2 - 3*(-1/3)2= 4*3/12+2*9/16-3*1/9=1+2 2/16 - 3/9 = 1 + 2 1/8 - 1/3 = 1 + 2 3/24 - 8/24 = 2 19/24   D) -1/2(xy)^2= -1/2(-3/4*(-1/3)^2=-1/2*(1/4)^2= -1/2*1/16= -1/32   2) A) 5 17/24 - (-2 3/8) = 5 17/24 + 2 9/24 = 8 2/24 = 8 1/12 B) (5 4/15 - 3 7/24) / 0,8 = (5 96/360 - 3 105/360): 8/10 = 1 351/360 : 8/10 = 711/360 * 10/8 = 7110/2880 = 2 1350/2880 = 2 135/288 = 2 15/32