$\bold{ELIMINATION\ METHOD}\\\\\left\{\begin{array}{ccc}y=-x+8\\y=x+4&\TEXT{change the signs}\end{array}\right\\\underline{+\left\{\begin{array}{ccc}y=-x+8\\-y=-x-4\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad0=-2x+4\qquad\text{add}\ 2x\ \text{to both sides}\\.\qquad2x=4\qquad\text{divide both sides by 2}\\.\qquad\boxed{x=2}\\\\\text{Put it to the second equation}\\y=2+4\\\boxed{y=6}$

$\bold{SUBSTITUTION\ METHOD}\\\\\left\{\begin{array}{ccc}y=-x+8&(1)\\y=x+4&(2)\end{array}\right\\\\\text{Substitute (1) to (2)}\\\\-x+8=x+4\qquad\text{subtract 8 from both sides}\\-x=x-4\qquad\text{subtract}\ x\ \text{from both sides}\\-x-x=-4\\-2x=-4\qquad\text{divide both sides by (-2)}\\\boxed{x=2}\\\\\text{Put it to the second equation}\\y=2+4\\\boxed{y=6}$

7 0

3 years ago

Plz help with numbers 9 and 10!

Vlada [557]

Question number 9
Angle 1 is 75. This is because If two parallel lines are cut by a transversal, the corresponding angles are congruent.

Angle 2 is 105. This is because If two parallel lines are cut by a transversal, the interior angles on the same side of the transversal are supplementary.

Question number 10
Angle 1 is 120. This is because If two parallel lines are cut by a transversal, the corresponding angles are congruent.

Angle 2 is 60. This is because If two parallel lines are cut by a transversal, the interior angles on the same side of the transversal are supplementary.

5 0

3 years ago

Bryce is making -pound hamburger patties. He was able to make of this size patty. Which equation can be used to find how much ha

Sindrei [870]

I really don't know I'm.bad at math

4 0

3 years ago