Spending money, since your amount of money is decreasing, which is negative
Answer:
since the unknown amount can buy 100 pencils
he bought 70 pencils
therefore $4.50 can buy 30 pencils
so 1 pencils cost $4.50 /30=0.15
Y = -2x + 6....so we sub in -2x + 6 for y in the other equation
3y - x + 3 = 0
3(-2x + 6) - x + 3 = 0
-6x + 18 - x + 3 = 0
-7x + 21 = 0
-7x = -21
x = -21/-7
x = 3
now we sub 3 in for x in either of the original equations to find y.
y = -2x + 6
y = -2(3) + 6
y = -6 + 6
y = 0
so ur solution is : (3,0)
12.5 is your answer! Hope I helped! :D