Answer:
x=8.499
y=0.167
Step-by-step explanation:
the equation says:x^2-9y^2=72....(1)
x+3y=9.......(2)
divide (2) from (1),it becomes:
x-3y=8
making x subject of formula,
x=8+3y....(3)
submitting (3) into (1),it becomes
(8+3y)^2-9y^2=72
64+48y=72
48y=72-64=8
y=8/48=0.167......(4)
submitting (4) into (2),it becomes
x+3(0.167)=9
x+0.501=9
x=9-0.501
x=8.499
