Answer:
The larger number is 12 and the smaller number is 9
Step-by-step explanation:
Let us first deal with the first sentence of this word problem.
Let's call the larger number L
and the smaller number S
.
We know from the first sentence:
3
L =
4
S
We know from the second sentence:
L+S =
21
Let's solve this second equation for
L-
L+S =
21
-
L
S =
21
-
L
Now we can substitute 21
-
L for S in the first equation and solve for L :
3L = 4 (21
-
L)
3L + 4L = 84 - 4L + 4L
7L = 84
7L/7 = 84/7
L = 12
Next we can substitute 12 for L in the solution to the second equation:
s = 21 - 12
s = 9