Question 39961
Let p be the number of pens and b be the number of bumper stickers.
Their costs are then .23p and .14b, respectively...so we have
p + b = 5000
.23p + .14b = 970
We can combine these by a linear sum by multiplying the first equation by 14 and the second by 100...then we subtract the equations...we get
14p + 14b = 70000
-(23p + 14b = 97000)
and get
-9p = - 27000
p = 3000
Thus he/she gave away 3000 pens and 2000 bumper stickers.