Question

Which equations are correct? Select each correct answer.

Answer 1

Answer:

Solution(s) : Option # 2 and # 4

Step-by-step explanation:

One quick way to identify which solutions are accurate would be adding the exponents of the terms provided ( b, y, c etc ). As you can see in each example two expressions are being multiplied, and hence the exponents of each term are being added.

Therefore the second and fourth example are correct, as 4 + 5 = 9, the co - efficient of y. And 3 + 4 = 7, the co - efficient of x.

Check :

$5y^4\left(2y^5\right)$ = $5\cdot \:2y^{4+5}$ = $5\cdot \:2y^9$ = $10y^9$

$5x^3\left(6x^4\right)$ = $5\cdot \:6x^{3+4}$ = $5\cdot \:6x^7$ = $30x^7$

Answer 2

Answers:

Option two, 5$y^{4}$(2$y^{5}$) = 10$y^{9}$ and option 4, 5$x^{3}$(6$x^{4}$) = 30$x^{7}$

Step-by-step explanation:

O1 + O3 = incorrect, the powers have been multiplied together. Laws of indices suggest that if you are multiplying powers together, you must add them, not do 4 x 5 or 2 x 2.

Please remember:

2y squared x 3y cubed = 6y to the power 5