Finish solving the system of equations –9.5x – 2.5y = –4.3 and 7x + 2.5y = 0.8 using the linear combination method. 1. Determine which variable will be eliminated: y will be eliminated because –2.5y and 2.5y are opposite terms.

2. Add the equations together to create a one-variable linear equation: –2.5x = –3.5

3. Solve to determine the unknown variable in the equation: x = 1.4

4. Substitute the value of the variable into either original equation to solve for the other variable.

The solution to the system is (
,

360 different combinations

example 2 – simplify: step 1: completely factor both the numerators and denominators of all fractions. step 2: change the division sign to a multiplication sign and flip (or reciprocate) the fraction after the division sign; essential you need to multiply by the reciprocal. step 3 : cancel or reduce the fractions.

answer: the angel abc is 30°,and the abc is a triangle where the angel bac is 90°

so ac is the half of 24=12ft,and from the pythagorean theorem we find ba

ba=√bc^2-ac^2=√576-144=√432=12√3ft

so bac is 12+12√3=12(1+√3)ft