Answer:
9. (7a + 6b – 9c) – (3a – 6c)
=7a+6b-9c-3a+6c
=7a-3a+6b-9c+6c
=4a+6b-3c
10. (x2 – 9) – (-2x2 + 5x – 3)
= x^2-9+2x^2-5x+3
=x^2+2x^2-5x-9+3
=3x^2-5x-6
11. (5 – 6d – d2) – (-4d – d2)
=5-6d- d^2+4d+ d^2
=5-6d+4d-d^2+ d^2
=5-2d
12. (-4x + 7) – (3x – 7)
=-4x+7-3x+7
= -4x-3x+7+7
=-7x+14
13. (4a – 3b) – (5a – 2b)
=4a-3b-5a+2b
=4a-5a-3b+2b
= -a-b
14. (2c + 3d) – (-6d – 5c)
=2c+3d+6d+5c
=2c+5c+3d+6d
=7c+9d
15. (5x2 + 6x – 9) – (x2 – 3x +7)
=5x^2+6x-9- x^2+3x-7
=5x^2- x^2+6x+3x-9-7
=4x^2+9x-16
16. (3y – 6) – (8 – 9y)
=3y-6-8+9y
=3y+9y-6-8
=12y-14
17. (3a2 – 2ab + 3b2) - (-a2 – 5ab + 3b2)
=3a^2-2ab+3b^2+ a^2+5ab-3b^2
=3a^2+ a^2-2ab+5ab+3b^2- 3b^2
=4a^2+3ab
18. 5c – [8c – (6 – 3c)]
=5c-[8c-6+3c]
=5c-8c+6-3c
=5c-8c-3c+6
= -6c+6
19. 10x + [3x – (5x – 4)]
=10x+[ 3x-5x+4]
=10x+3x-5x+4
=8x+4
20. 3x 2 – [7x- (4x – x2) + 3]
=3x^2-[7x-4x+ x^2+3]
=3x^2-7x+4x- x^2-3
=3x^2-x^2-7x+4x-3
=2x^2-3x-3
21. x2 – [ - 3x+ ( 4 – 7x)]
= x^2-[ -3x+4-7x]
= x^2+3x-4+7x
= x^2+3x+7x-4
= x^2+10x-4
First you should round the numbers that you are multiplying so.
56 ---> 60
27---> 30
You know that 5 and higher you'll round up.
4 and below you'll round down.
Your answer is <em>infinitely</em><em> </em><em>many</em><em> </em><em>solutions</em><em> </em>
Step-by-step explanation:
-4x+-20=-4x-20
+4× +4x
(4x cancel out)
Your left with
-20=-20
Therefore your answer is infinitely many solutions
Answer:
Option 2
Step-by-step explanation:
When completing the square, you have to find the number that will allow you to find the perfect square trinomials and when you factor that it should get the form a^2 + 2ab + b^2 and if a is equal to 1, then to find b, you have to take the half of the coefficient and square it because of the equation, and to maintain a balanced equation, you have to add it to both sides (same to both sides)
Hope this helped.
Answer:
The ball will be the 7 ft high at 2 different times.
Step-by-step explanation:
The height in meters of the ball is given by the following equation:
7 feet high
The height, by the equation, is given in meters, so we have to work in meters. Since each feet has 0,3048 meters, 7 feet have have 2.1336 meters. So, we have to solve the following equation
At how many different times will the ball be 7 ft. High?
We have to find the number of solutions for the equation above.
It is given according to the value of 
. If it is positive, there are two solutions, zero one solution and negative no solutions.
In this equation 
. So
Since the coefficient is positive, the ball will be the 7 ft high at 2 different times.
