Answer:

Step-by-step explanation:
The method of variable substitution is a way of solving a system of equations. It involves solving one equation for a variable and then substituting in the expression that represents the value of the solved variable into the other equation. After doing so, one can solve for the unknown variable and then backsolve for the other variable.

In this system, the second equation is already solved for (y), thus one can substitute that expression into the other equation in the system.

Now solve using inverse operations,

Backsolve to find the value of (y), substitute in the value of (x), and solve for the value of (y).

Substitute,

Solve,

Thus, the answer to this system of equations is the following,
.
Answer:
15 pieces
Step-by-step explanation:
a ratio of 1:3 has 4 total parts, meaning that each part is 5.
20/3 = 15 so that means he has 5 pieces of chocolate and 15 of hard candy.
Answer C
Step-by-step explanation:
Answer:
∠ GDH = 67.5°
Step-by-step explanation:
The measure of the chord- chord angle GDH is half the sum of the measures of the arcs intercepted by the angle and its vertical angle.
∠ GDH =
(GH + EF) =
(90 + 45)° = 0.5 × 135° = 67.5°