For me, it’s easiest when i distribute the negative sign if i need to and then reorder to put the like terms together. and then solve.
(also sorry if it’s a little confusing with all the parentheses, i use them because it helps me organize everything)
21. (4x-9y) + (6x+10) + (8y-4)
= 4x + 6x - 9y + 8y + 10 - 4
= 10x - y + 6
—> D
22. (6x+9y-15) + (2x-9y+8)
= 6x + 2x + 9y - 9y - 15 + 8 (the 9y - 9y = 0, so you can leave it out of the final equation)
= 8x - 7
—> D
23. (9x^2-8x+3) - (5x^2-6x+4)
= 9x^2 - 8x + 3 - 5x^2 -(-6x) - 4
= 9x^2 - 5x^2 - 8x + 6x + 3 - 4 (remember that two - signs next to each other make a + sign)
= 4x^2 - 2x - 1
—> A
24. (9x^3-7x+8) - (5x^2+7x-10)
= 9x^3 - 7x + 8 - 5x^2 - 7x -(-10)
= 9x^3 - 5x^2 - 7x - 7x + 8 + 10
= 9x^3 - 5x^2 - 14x + 18
—> D
25. (6x+14y) - ((7x+5y) + (x-8y))
= (6x+14y) - (7x + x + 5y - 8y)
= (6x+14y) - (8x-3y)
= 6x + 14y - 8x -(-3y)
= 6x - 8x + 14y + 3y
= -2x + 17y
—> B
Answer:
15 kg
Step-by-step explanation:
Radius of a solid sphere : mass of a solid sphere
3 cm : 9 kg
Find the mass of a sphere of the same material of radius 5 cm
Radius of a solid sphere : mass of a solid sphere
5 cm : x kg
Equate both ratios to find x
3 cm : 9 kg = 5 cm : x kg
3/9 = 5/x
3 * x = 9 * 5
3x = 45
x = 45/3
x = 15 kg
The mass of a sphere of the same material of radius 5 cm is 15 kg
Answer:
6 hours
Step-by-step explanation:
if it costs 12 dollars to rent it at first then that subtracts 12 dollars from the total 30.
this leaves you with 18 buck, divide 18 by 3 and you get 6, she had it for 6hours
You have to turn them in to the lowest common denominator
