Let's call the 13¢ stamps a and the 18¢ stamps b:
a+b = 42 and therefore a= 42-b (formula 1)
0.13a+0.18b= 6.66 In this formula, substitute the value of a according to formula 1:
0.13(42-b)+0.18b= 6.66 Multiply on the left to get rid of the parenthesis:
5.46-0.13b+0.18b= 6.66 Subtract 5.46 from both sides:
-0.13b+0.18b= 1.20 Add on the left:
0.05b= 1.20 Divide both sides by 0.05
b= 24 You have 24 18¢ stamps and:
42-24= 18 13¢ stamps
Check: (24 x 0.18) + (18 x 0.13)= 6.66 Correct.
Answer:
x=13
Step-by-step explanation:
First, you add the x's together: 2x+x=3x
Now you have:3x-1=38
Add 1 to both sides: 3x=39
1 cancel on the left side of the equation
Divide 3 on both sides: x=39/3
3 cancels on the left side and 39 divided by 3 is 13:
x=13
Hope this helps!
Look at the problem and do it in order
Faith has a ratio green:red of 24:6 which equals 4:1 which is >1
Faith is the answer
-2y-11=Z
n/4 -5=m
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