Question

计算80×3.5^2+160×3.5×1.5+80×1.5^2

Answer 1

80×3.5^2+160×3.5×1.5+80×1.5^2

=80×(3.5^2+2×3.5×1.5+1.5^2)

=80×(3.5+1.5)^2

=80×25

=2000