已知:△ABC≌△A′B′C′,∠A=35°,∠B=75°则∠C′的度数为 .
计算5x2y•(-3xy3)=_______;-3xy(2x-3y)=_______.
计算:(-9x2+3x)(-3x)=______.
计算:4x•(2x2-3x+1)=_______.
.
4a2b2+(ab)2=________.