已知:8y^3=-27,16(x-2)^2=121,求:x+y的值?
问题描述:
已知:8y^3=-27,16(x-2)^2=121,求:x+y的值?
答
8y^3=-27 16(x-2)^2=121 y=-27/8 (x-2)=121/16 y=-3/2 x-2=11/4;x-2=-11/4 x⒈=19/4;x⒉=-3/4 ㈠x+y=-3/2+(-3/4)=-9/4; ㈡x+y=-3/2+19/4=13/4.