Question

Hurry Quick, help me do this problem. I don't understand how to do this so please help! (Problem in photo)

Answer 1

Answer:

1) The system of equations is $5x+4y=75$ and $x+y=18$

2) The first number is $3$ and the second number is $15$

Step-by-step explanation:

1) Let be "x" the first number and "y" the second number.

Remember that:

a- The word "times" indicates multiplication.

b- A sum is the result of an addition.

c- "Is" indicates this sign:  $=$

Then, the sum of 5 times "x" and 4 times "y" is 75, can written as:

$5x+4y=75$

And "The sum of the two numbers is 18" can written as:

$x+y=18$

Therefore, the System of equations is:

$\left \{ {{5x+4y=75} \atop {x+y=18}} \right.$

2) You can use the Elimination Method to solve it:

- Multiply the second equation by -5, add the equations and then solve for "y":

$\left \{ {{5x+4y=75} \atop {-5x-5y=-90}} \right.\\......................\\-y=-15\\\\y=15$

- Substitute the value of "y" into any original equation and solve for "x":

$x+15=18\\\\x=18-15\\\\x=3$