A=3B
4.35A+5.40B=780.95
Substitute 3B into A for the second equation:
4.35(3B)+5.40B=780.90
13.05B+5.40B=780.90
18.45B=780.90
B=42.33
Plug into equation 1:
A=3B
A=3(42.33)
A=126.98
nearest 1000: 920,000
nearest 100: 919,800
nearest 10 (you said 100 but I think you mean 10): 919,830
2m-4 = x+nx switch sides
2m-4 = x (1+n) common factor
2m-4/1+4 = x divide both side by 1-x
Similarities: They both are polynomials of degree 2, both of their graphs is a parabola, both have either 2 or 0 real solutions, they are both continuous functions over R
(DOS= difference of two squares, PST=perfect square trinomial
Differences: PST has three terms, whereas the difference of squares has 2. PST's factors are both the same, whereas DOS's elements are conjugates of each other. DOS can always be factored into two distinct polynomials with rational coefficients, whereas PST has two same polynomial factors.
A.
because the total distance of every triangle 180. Add the two other angles so 42+ 57 =99. Then you have to subtract those two combined angles to find the missing one from the total distance, which is 180. 180-99=81. the answer is A. 81