X=2y-1 3x-3y=9
a. substitution; (7,4)
b. elimination using multiplication; (3, 2)
C. substitution; (4,7)
d. elimination using multiplication; -21,-10)

Ahiker stands at an unknown elevation before he ascends 2 miles up a mountain to an elevation of 9 miles. find the elevation of the hiker before his ascent.

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.

42. if 20 men can eat 200 kg of wheat in 40 days, then 10 men can eat 300 kg of wheat in how many days? a) 120 days b) 60 days c) 80 days d) none of these