Can someone explain what a highest common factor in algebra is? ?

See below.

Step-by-step explanation:

Yes it is the highest value factor that will divide into 2 or more algebraic expressions.

For example

x^2 and x^3  have HCF = x^2.

3y^2 and 6y  have HCF = 3y.

4xy^2 and 6 x^2y^2  have an HCF =  2xy^2.

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer