Short answer: C
Remark
Since b is all by itself in equation 2, Substitute it into equation 1.
2a + 3b = 5
b = a - 5 Put this result in equation 1. Be sure and use brackets.
2a + 3(a - 5) = 5 Remove the brackets.
2a + 3a - 15 = 5 Notice the -5 inside the brackets becomes - 15
Combine like terms on the left.
5a - 15 = 5 Add 15 to both sides
5a = 5 + 15
5a = 20 Divide by 5
a = 20/5
a = 4
So far, c is the only possible answer.
b = a - 5
b = 4 - 5
b = - 1
Answer:


Step-by-step explanation:
Consider triangles AMP and ADC. In these triangles,
- angle A is the common angle, so
by reflexive property; - angles AMP and ADC are congruent as corresponding angles when two parallel lines MP and CD are cut by transversal AD.
Hence, triangles AMP and ADC are similar by AA similarity theorem.
Similar triangles have proportional corresponding sides, thus

so

Consider triangles ACB and PCN. In these triangles,
- angle C is the common angle, so
by reflexive property; - angles ABC and PCN are congruent as corresponding angles when two parallel lines PN and AB are cut by transversal BC.
Hence, triangles ACB and PCN are similar by AA similarity theorem.
Similar triangles have proportional corresponding sides, thus

so

-1 is the answer
If the variable is by itself or you don't see a coefficient, the coefficient is always 1
Answer:
B
Step-by-step explanation:
Combine like terms. Like terms have same variable with same power.
2x & (-12x) are like terms and
-7x² & 4x² are like terms
A = 2x - 7x² + 3
B = 4x² - 12x
A + B = 2x - 7x² + 3 + 4x² - 12x
= <u>2x - 12x</u> <u>- 7x² + 4x²</u> + 3
= (2-12)x + (-7 + 4)x² + 3
= -10x + (-3x²) + 3
= -3x² - 10x +3