Answer:
-6
Step-by-step explanation:
We know that since Ax + By = 3 passes through (-7, 2), then if we plug -7 in for x and 2 in for y, the equation is satisfied. So, let's do that:
Ax + By = 3
A * (-7) + B * 2 = 3
-7A + 2B = 3
We also know that this line is parallel to x + 3y = -5, which means their slopes are the same. Let's solve for y in the second equation:
x + 3y = -5
3y = -x - 5
y = (-1/3)x - (5/3)
So, the slope of this line is -1/3, which means the slope of Ax + By = 3 is also -1/3. Let's solve for y in the first equation:
Ax + By = 3
By = -Ax + 3
y = (-A/B)x + 3/B
This means that -A/B = -1/3. So, we have a relationship between A and B:
-A/B = -1/3
A/B = 1/3
B = 3A
Plug 3A in for B into the equation we had where -7A + 2B = 3:
-7A + 2B = 3
-7A + 2 * 3A = 3
-7A + 6A = 3
-A = 3
A = -3
Use this to solve for B:
B = 3A
B = 3 * (-3) = -9
So, B = -9 and A = -3. Then B - A is:
B - A = -9 - (-3) = -9 + 3 = -6
The answer is -6.
<em>~ an aesthetics lover</em>
Answer:
b
Step-by-step explanation:
because we can not some times change the places in addition so b is the correct answer
First, find out x
x+15+2x+15=180
3x+30=180
3x=150
x=50
so the two angels are x+15=65(let's name is ∠5 for convenience), and ∠6= 2x+15=115
notice the two inner lines are marked as congruent, so
∠4=∠5=65
∠1=180-∠4-∠5=180-65-65=50
Name the right bottom angle ∠7, ∠3=∠7 and ∠3+∠7=the exterior angle 100 degree, therefore, ∠3=50
∠2+∠3=∠4, therefore, ∠2=∠4-∠3=65-50=15
∠1=50, ∠2=15, ∠3=50, ∠4=65
