Respuesta :
Answer:
1st number is 64
Step-by-step explanation:
Lets start by making the words into equations.
So the 1st plus the 2nd is 75:
1st+ 2nd= 75
Now the tricky part. The 1st is 9 more than 5 times the 2nd. The key word 'times' means multiplication, we we will have 5 x 2nd somewhere in our equation. The '1st is 9 more than' part tricks us into thinking we will have 1st plus 9, BUT WE WON'T because it isn't 9 more, its 9 more THAN. This means we will get.
1st= 5 x 2nd +9
To make this a little cleaner, I will have the 1st = X and the 2nd= y.
x+y=75
x=5y+9
We can substitute the bottom equation into the top equation.
5y+9+y=75
Combine like terms
6y+9=75
Solve for Y by getting y alone.
6y+9=75
6y=66
y=11
Then we can take our value of y and plug it back into either equation to solve for X. The top equation is the easiest.
x+11=75
Isolate x to solve for x
x=64
And we established that x= the 1st number, so the 1st number is 64
