Answer :
Answer:
Step-by-step explanation:
a+b = 22 -- equation 1
6.20a + 7.40b = 150.80 replacing decimals
620a + 740b = 15080 --- equation 2
From eq. 1 a = (22 - b)
putting a's value in equation 2
620(22 - b) + 740b = 15080
13640 - 620b + 740b = 15080
120b = 15080 - 13640
b = 1440/120 = 12
From equation 1 a + 12 = 22
a = 10
Verify your answer by equation 2 putting the value of a and b
620*10 + 740*12 = 15080
We could write the following equations according to the problem:
Hours equation:
[tex]a+b=22[/tex]And, the payment equation: (cents)
[tex]620a+740b=1508[/tex]We could solve this system of equations using the elimination method:
[tex]\begin{cases}a+b=22 \\ 620a+740b=1508\end{cases}[/tex]We're going to multiply the first equation by -620:
[tex]\begin{cases}-620a-620b=-13640 \\ 620a+740b=15080\end{cases}[/tex]Now, we're going to sum both equations eliminating variable a, so we get a linear equation in terms of b:
[tex]\begin{gathered} 120b=1440 \\ b=12 \end{gathered}[/tex]Now we know that he did 12 hours at job b.
As he worked 22 hours in total, then he worked 10 hours at job a.
