In an isosceles triangle, the base angles are congruent. The third angle is called the vertex angle.
Here, the vertex angle is <A.
Therefore, m<C = m<B.
m<A = 3m<B + 20
m<A + m<B + m<C = 180
3m<B + 20 + m<B + m<B = 180
5m<B + 20 = 180
5m<B = 160
m<B = 32
m<C = m<B = 32
Answer: m<C = 32 deg
So to find the answer you want to isolate the y. So the first thing you want to do is to move everything to the opposite side of the = sign. You start by adding 10 to both sides.
10+ 5y -10 = -25 +10
5y = -15.
the tens cancel out on the left side and on the right you get left with -15/
Since y is being multiplied by 5 you always want to do the opposite so you divide by 5.
5y/5 = -15/5
y = -3
It's hard to explain but you just have to remember that what you do to one side you must do to the other to keep the equation balanced.
The complete statements are as follows;
The variable is represented by<u> one </u><u>orange </u><u>x </u><u>tiles</u><u>.</u>
Subtract three is represented by <u>three</u><u> </u><u>blue</u><u> - tiles</u>.
The tiles represent <u>subtraction</u> <u>3</u> from an unknown number.
<h3>What are algerbra tiles?</h3>
Algebra tiles are square and rectangle shaped tiles or tiles that represent numbers and variables.
Given
Use the algebra tiles to model x -3.
The complete statements are as follows;
The variable is represented by<u> one </u><u>orange </u><u>x </u><u>tiles</u><u>.</u>
Subtract three is represented by <u>three</u><u> </u><u>blue</u><u> - tiles</u>.
The tiles represent <u>subtraction</u> <u>3</u> from an unknown number.
To know more about algerbra tiles click the link given below.
brainly.com/question/81876
3x+y=17
=> 3x=17-y
Again, x+3y=-1
=> 3y= -1-x
now, 3x+3y= (17-y)+(-1-x)
= 17-y-1-x
= 16-x-y