Step-by-step explanation:
<em>Combine like terms</em>
a. 2r + 3 + 4r = (2r + 4r) + 3 = 6r + 3
b. 8 + 3d + d = (3d + d) + 8 = 4d + 8
c. mn + (-3mn) + 6 = (mn - 3mn) + 6 = -2mn + 6
d. 10s + (-10) + (-4s) = (10s - 4s) - 10 = 14s - 10
<em>Terms are called "like terms" if they have the same variable part (the same letters in the same powers). Like terms differ at most coefficient.</em>
Answer:
-12x+18x²
Step-by-step explanation:
Given: 
Distributive property of multiplication under which a number is multiplied by the sum of two number, the first number can be distributed to both of those number.
∴ 
solving it by using distributive property
= 
= 
Opening parenthesis
= 
Hence, -12x+18
is the result after using distributive property.
If x=students, the equation would be x=12 (x is less than of equal to twelve). I don’t know what you mean by constraints; perhaps if you explain more, I could help?
Answer:(1) The correct option is b. (2) The correct option is c.
Explanation:
(1)
It is given that the △ABD≅△FEC.
So by (CPCTC) corresponding parts of congruent triangles are congruent.

It is given that the angle DAB is 63 degree.

Therefore, the correct option is b.
(2)
It is given that the △ABD≅△FEC.
So by (CPCTC) corresponding parts of congruent triangles are congruent.




Therefore, the correct option is c.