exam Maths Puzzle Numerical Ability

please show me how to solve by substitution 3x=-7
x+y=-9 I am not sure what to substtiute.

Read Solution (Total 0)

exam Other Question

A coffee merchant has coffee beans that sell for $9.00 per lb and $12.00 per pound. The two types are to be mixed to create 100 lbs of a mixture that will sell for $11.25 per pound A purse has P218 in P10, P5, and P1 Coins. There are 46 coins in all and there are 4 more P5 coins than the P10 coins. How many of each kind of coin are there?? hope you can help me...