Before we begin, remember the following:
-ve * -ve = +ve
-ve * +ve = -ve
+ve * -ve = -ve
+ve * +ve = +ve
Now, for each of the given expression, we will expand the brackets, combine like terms and then compare the final output with the given expressions.
First expression:
(x² + 15x + 65) + (2x - 5)(3x + 8)
x² + 15x + 65 + (2x*3x + 2x*8 - 5*3x - 5*8)
x² + 15x + 65 + (6x² + 16x - 15x - 40)
x² + 15x + 65 + 6x² + 16x - 15x - 40
x²(1+6) + x(15+16-15) + 65-40
7x² + 16x + 25
This expression corresponds to letter B
Second expression:
(4x + 1)(3x - 4) - (5x² - 10x - 12)
4x(3x) + 4x(-4) + 1(3x) + 1(-4) - (5x² - 10x - 12)
12x² - 16x + 3x - 4 - 5x² + 10x + 12
x²(12-5) + x(-16+3+10) - 4+12
7x² - 3x + 8
This expression corresponds to letter D
Third expression:
(8x² + 19x + 4) + (3x + 2)(x - 5)
8x² + 19x + 4 + (3x*x + 3x*(-5) + 2*x + 2*(-5))
8x² + 19x + 4 + (3x² - 15x + 2x - 10)
8x² + 19x + 4 + 3x² - 15x + 2x - 10
x²(8+3) + x(19-15+2) + 4-10
11x² + 6x - 6
This is equivalent to letter A
Fourth expression:
(6x + 1)(3x - 7) - (7x² - 34x - 20)
6x(3x) + 6x(-7) + 1(3x) + 1(-7) - (7x² - 34x - 20)
18x² - 42x + 3x - 7 - 7x² + 34x + 20
x²(18-7) + x(-42+3+34) - 7+20
11x² - 5x + 13
This is equivalent to letter C
Hope this helps :)
This is an exponential table
Answer:
20 is 80% of 25
Step-by-step explanation:
We assume, that the number 25 is 100% - because it's the output value of the task.
2. We assume, that x is the value we are looking for.
3. If 100% equals 25, so we can write it down as 100%=25.
4. We know, that x% equals 20 of the output value, so we can write it down as x%=20.
5. Now we have two simple equations:
1) 100%=25
2) x%=20
where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:
100%/x%=25/20
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.
7. Solution for 20 is what percent of 25
100%/x%=25/20
(100/x)*x=(25/20)*x - we multiply both sides of the equation by x
100=1.25*x - we divide both sides of the equation by (1.25) to get x
100/1.25=x
80=x
x=80
Answer:
16
Step-by-step explanation:
4×.75=3
8×.75=6
16×.75=12
20×.75=15
Answer:
x=4
Step-by-step explanation:
4x-6 + 2x = 18
Combine like terms
6x -6 = 18
Add 6 to each side
6x-6+6 =18+6
6x = 24
Divide each side by 6
6x/6 = 24/6
x =4
