Question

0,2x³+¾y⁴-1,2x³+0,75y⁴ при x=-3 и y=25

Answer 1

$0,2x^{3}+\frac{3}{4}y^{4}-1,2x^{3}+0,75y^{4}=(0,2-1,2)x^{3}+(0,75+0,75)y^{4}=-x^{3}+1,5y^{4} \\\\x=-3;y=25 \Rightarrow -x^{3}+1,5y^{4} =-(-3)^{3}+1,5*25^{4}=27+585937,5=\\=585964,5$

Answer 2

To evaluate the expression 0.2x³ + 0.75y⁴ - 1.2x³ + 0.75y⁴ at x = -3 and y = 25, we substitute these values into the expression and perform the calculations.

Substituting x = -3 and y = 25:

0.2(-3)³ + 0.75(25)⁴ - 1.2(-3)³ + 0.75(25)⁴

Simplifying the terms:

0.2(-27) + 0.75(625) - 1.2(-27) + 0.75(625)

-5.4 + 468.75 + 32.4 + 468.75

Combining like terms:

-5.4 + 32.4 + 468.75 + 468.75

494.55

Therefore, when x = -3 and y = 25, the expression 0.2x³ + 0.75y⁴ - 1.2x³ + 0.75y⁴ evaluates to 494.55.