Question

multiply the following and verify the result for x=1,y=-2 and z=3​

Answer 1

Step-by-step explanation:

2

x

3

y

3

×(3x−15y)

=

3

2

x

3

y

3

⋅3x−

3

2

x

3

y

3

⋅15y

=2x

4

y

3

−10x

3

y

4

Now, for x=2,y=−1, we have

L.H.S.-

3

2

x

3

y

3

×(3x−15y)

=

3

2

(2)

3

(−1)

3

×(3⋅2−15⋅(−1))

=

3

2

⋅8⋅(−1)×(6+15)

=(−

3

16

)×21

=−112

R.H.S.-

2x

4

y

3

−10x

3

y

4

=2(2)

4

(−1)

3

−10(2)

3

(−1)

4

=2⋅16⋅(−1)−10⋅8⋅1

=−32−80

=−112

∵ L.H.S. = R.H.S.

Hence verified.

Answer 2

Answer:

42

Step-by-step explanation:

Question -7yz(x^2y +3x^3)

= -7×-2×3(1^2×-2+3×1^3)

= 42(-2+3)

= 42(1)

= 42