当x=3 y=1.2时4x²-3y=( )

问题描述:

当x=3 y=1.2时4x²-3y=( )

当x=3 y=1.2时
4x²-3y=4×3²-3×1.2=36-3.6=32.4

=4×9-3×1.2
=36-3.6
=32.4