
Solve the following using Substitution method
2x – 5y = -13
3x + 4y = 15


- To solve a pair of equations using substitution, first solve one of the equations for one of the variables. Then substitute the result for that variable in the other equation.

- Choose one of the equations and solve it for x by isolating x on the left-hand side of the equal sign. I'm choosing the 1st equation for now.

- Add 5y to both sides of the equation.


- Multiply
times 5y - 13.

- Substitute
for x in the other equation, 3x + 4y = 15.

- Multiply 3 times
.

- Add
to 4y.

- Add
to both sides of the equation.

- Divide both sides of the equation by 23/2, which is the same as multiplying both sides by the reciprocal of the fraction.

- Substitute 3 for y in
. Because the resulting equation contains only one variable, you can solve for x directly.


- Add
to
by finding a common denominator and adding the numerators. Then reduce the fraction to its lowest terms if possible.

- The system is now solved. The value of x & y will be 1 & 3 respectively.

Answer:
396
Step-by-step explanation:
Difference of two squares is breaking down numbers into pieces and using the distributive property to solve. The pieces should be in the form (a-b)(c+d).
Write 22 as (20 + 2) and 18 as (20-2).
(20+2)(20-2) = 400 + 40 - 40 - 4 = 400 - 4 = 396
6 times because you find the common denominator which is 8 so 3/4 is 6/8. He needs to fill his cup 6 times.
Answer:
D is the largest angle
Step-by-step explanation:
The angle opposite the largest side is the largest and the angle opposite the smallest side is the smallest.
Since 12 is the largest side, angle D is the largest
8 is the smallest side, F is the smallest angle