4a + 7b = 38 -> (1)
9a + 7b = 68 -> (2)
Subtract (1) from (2),
9a - 4a + 7b - 7b = 68 - 38
5a = 30
a = 6
Answer:
3/10
Step-by-step explanation:there are 10 marbles all together three blue ones
Step One
Find AM
Formula
AM = MN - AN
Givens
MN = 67.2
AN = 32
Solution
AM - 67,2 - 32
AM = 35.2
Step Two
Set up a solution
67.2/35.2 = 81.9/x Cross Muliply
67.2 * x = 81.9 * 35.2 Combine the right
67.2 * x = 2882.88 Divide by 67.2
x = 2882.88/67.2
x = 42.9 Answer
R - 10/3 + 1/2 = -11/6...if u multiply everything by the common denominator 6, it will get rid of the fractions.
(6)r - 6(10/3) + 6(1/2) = 6(-11/6)
6r - 60/3 + 6/2 = - 66/6...simplify
6r - 20 + 3 = - 11
6r - 17 = -11
6r = -11 + 17
6r = 6
r = 6/6
r = 1 <===
