Question

Multiply: (3x + 7)(5x2 − 3x + 6) A) 15x3 + 26x2 − 39x + 42 B) 15x3 + 26x2 + 3x + 42 C) 15x3 − 44x2 − 3x + 42 D) 15x3 + 26x2 − 3x + 42

Answer 1

Answer:

38.5

Step-by-step explanation:

Lets say, first number = x

Second number = 3x+7

Total = 49

(x)+(3x+7)= 49

4x+7 = 49

4x = 42

x = 42/4

x= 10.5

x= 10.5

3x+7 = 3(10.5)+7 = 38.5

Hope this helps!!

Answer 2

Answer:

$15x^3+26x^2-3x+42$

Step-by-step explanation:

Multiply $(3x + 7)(5x^2 - 3x + 6)$

To multiply two parenthesis , we first multiply 3x inside the second parenthesis and then we multiply 7 inside the second parenthesis

$(3x)(5x^2 - 3x + 6)=15x^3-9x^2+18x$

Now multiply 7 inside the second parenthesis

$(7)(5x^2 - 3x + 6)=35x^2-21x+42$

Now we add both the answers we got

$15x^3-9x^2+18x + 35x^2-21x+42$

Lets combine like terms

$15x^3+26x^2-3x+42$