CPM Homework Help : INT1 Problem 7-11

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Home > INT1 > Chapter 7 > Lesson 7.1.1 > Problem 7-11

7-11.

Solve the systems of equations below.

Hint:

Read the Math Notes box in Lesson 6.2.3 to review the Substitution Method. Use it to solve both parts.

$y = 3x$
$2y - 5x = 4$
Step 1(a):
To start part (a) substitute $3x$ in for $y$ into the second equation $2y − 5x = 4$ . So $2(3x) − 5x = 4$ .
Step 2(a):
Solve for $x$ .
Step 3(a):
Once you solve for $x$ , substitute that value in for $x$ into one of the original equations: $y = 3x$ or $2y − 5x = 4$ .
Solve for $y$ .
Answer (a):
Put the answer in point form $(x, y)$ .
The final answer is $(4,12)$ .

$x - 4 = y$
$-12 = 3y - 3x$
Step 1(b):
Substitute ( $x − 4$ ) in for $y$ in the second equation
$-12 = 3(x-4) − 3x$ .
Step 2(b):
Follow steps $2$ and $3$ from part (a).
Hint (b):
Read the Math Notes box in Lesson 6.4.1 to review the different types of solutions for systems of equations.

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