Total: 73
dogs: x
cats: 2x+10
2x+10+x=73
3x+10=73
3x=63
x=21
dogs: x
dogs: 21
cats: 2x+10
cats: 52
Check answer:
cats+dogs=73
52+21=73
There's no need for a system of linear equations if you were to solve a real life problem like this. In calculus, they don't give a rat about HOW you get your answer to an easy algebra 1 equation, as long as you used one of the correct methods and got the right answer.
Best of luck my friend. :)
Answer:

Here,
denotes the required number.
Step-by-step explanation:
Let
denotes the required number that satisfies the following condition.
''seven times a number is less than or equal to a quantity that is 24 less than that same number''
Seven times a number is equal to 
Quantity that is 24 less than that same number is equal to 
Now find the inequality.
As seven times a number is less than or equal to a quantity that is 24 less than that same number,

The answer is (3+5i)-(2+i)
Two angles are supplementary when they <span>add up to 180 degrees </span>⇒
m∠1 + m∠2 = 180°
4y + 7 + 9y + 4 = 180
13y + 11 = 180
13y = 180 - 11
13y = 169
y = 169/13
y = 13
m∠2 = 9y + 4 = 9 * 13 + 4 = 121°