How do you evaluate 2x ^ { 2} y if x = 2\frac { 1} { 2} ,y = - 3\frac { 3} { 5}?

2 Answers
Oct 4, 2017

2x^2y=-45

Explanation:

You can evaluate 2x^2y by subbing in the given points, x=2 1/2 and y=-3 3/5.

First, it's best to turn these fractions into improper fractions:
x=5/2
y=-18/5

Subbing these into the expression we get:
2x^2y
=2(5/2)^2(-18/5)
=2(25/4)(-18/5)

These fractions can be further simplified before you multiply them together:

=1(25/2)(-18/5)
=5/2(-18/1)
=5/1(-9)
=-45

So in short, 2x^2y=-45

Oct 4, 2017

-45

Explanation:

"change the mixed numbers into "color(blue)"improper fractions"

rArr2 1/2=5/2" and "3 3/5=18/5

rArr2x^2y

=2xx(5/2)^2xx-18/5

=2xx25/4xx-18/5

color(blue)"cancel common factors " on numerators/denominators.

=cancel(2)^1xxcancel(25)^5/cancel(4)^2xx-18/cancel(5)^1

=1xx5/cancel(2)^1xx-cancel(18)^9/1

=1xx5xx-9=-45