Rewrite equations:
x+y=14;42x+25y=486
Step: Solvex+y=14for x:
x+y=14
x+y+−y=14+−y(Add -y to both sides)
x=−y+14
Step: Substitute−y+14forxin42x+25y=486:
42x+25y=486
42(−y+14)+25y=486
−17y+588=486(Simplify both sides of the equation)
−17y+588+−588=486+−588(Add -588 to both sides)
−17y=−102
−17y
−17
=
−102
−17
(Divide both sides by -17)
y=6
Step: Substitute6foryinx=−y+14:
x=−y+14
x=−6+14
x=8(Simplify both sides of the equation)
On Fri, Sep 20, 2019 at 12:08 PM ESQULESE BLACK wrote:
The <em><u>correct answers</u></em> are:
Supplementary; ∠2 and ∠3; substitution; 2.
Explanation:
Supplementary angles are angles whose measures sum to 180°. Thus this is the first answer.
Since we are told that ∠2 and ∠3 are supplementary, their measures sum to 180° and they are the second answer.
We know that m∠1 + m∠2 = 180° and m∠2 + m∠3 = 180°. We can substitute "m∠2 + m∠3" for 180° in the first equation; this is the substitution property.
To isolate m∠1 on the right, we will subtract m∠2 from each side, and get that m∠1 = m∠3 and the angles are congruent.
If you use the first answer, the equation becomes 2x + 2y = 16. You could subtract this from equation Q to eliminate x.
The second answer makes equation P -2x - 2y = -16. You could add this to equation Q to eliminate x. You can use both of these methods to eliminate the x term, but if you can only choose one, you should choose the second option.
