Answer:
C. -7x^2 - 28
Step-by-step explanation:
Firstly simplify the bracket before doing anything;
4x(3x - 7) = 12x^2 - 28x
then go back to the question and substitute the expression(12x^2 - 28x) on the bracket and then work out the question;
12x^2 - 28x -19x^2...then group the values with the same exponent of x,
(12x^2 - 19x^2) - 28x
; -7x^2 - 28x
So first, you want to open the parenthesis here.
So, to do that, first look at the symbol before the parenthesis.
In this case it's a -.
So when it's a -, reverse the symbol inside the parenthesis. (This is because if you don't you're subtracting 2x and then adding 8, when really you're subtracting both 2x and 8.)
So,
9x - 2x - 8
Or simplified,
7x - 8
Answer:
a=-8
b=-29
Step-by-step explanation:
Let's assume
first number is a
second number is b
the difference of two numbers,a and b,is 21
so, we get
we can solve for 'a'
the difference of five times a and two times b is 18
so, we get
now, we can plug 'a'
now, we can solve for b
now, we can find 'a'
