9x-30 I’m pretty sure!
We are finding the difference, which means subtract! Nine times a number would be 9x and since it’s difference you would subtract it by 30.
It's a simultaneous equation:
Steps:
1.Number the equations..
a+b=77 -1
a-b=13 -2
2. Choose what variable you want to use. In this case I would use the "b". Since the signs in front of the "b's" are different, add the two equations together
a + b = 77
+ + +
a (-b) = 13
Which gives;
2a = 90
Then solve to find a:
2a=90
a= 90/2
a=45
3.Then plug the "a" value into any of the original equations to find the "b" value. I would use equation 1 since the all the variables are positive.
a + b = 77
(45) + b = 77
b=77-45
b=32
4.Solution
a=45
b=32
Pick 1: 6 yellow out of 15 total marbles = 6/15 = 2/5
Pick 2: 6 yellow out of 15 total marbles = 6/15 = 2/5
Pick 1 AND Pick 2
2/5 x 2/5 = 4/25
Answer:
2
Step-by-step explanation:
Answer:
h= 24
Step-by-step explanation:
r= 7
1230.88=3.14×7^2×h/3
1230.88= 153.86h/3
h=1230.88/153.86
h= 24
