eq^2: 7x=84 divide 84 by 7 which is 12.
therefore x is equal to 12. Then
1) take that 12 you got in equation 2 and substitute in equation 1 which is:
7x-12y=180
7(12)-12y=180
84 -12y=180
-12y=180-84
-12y=96 ............divide both sides with -12
-y=8 (×-1) both sides
y= -8
therefore 7(12)-12(-8)=180
Corrected Question
Sue travels by bus or walks when she visits the shops. The probability that she catches the bus to the shops is 0.4. The probability she catches the bus from the shops is 0.7. Show the probability that Sue walks at one way is 0.72
Answer:
(Proved)
Step-by-step explanation:
Sue travels by bus or walks when she visits the shops.
Let the event that she catches the bus to the shop=A
Let the event that she catches the bus from the shop=B
P(A)=0.4
P(B)=0.7
Both A and B are independent events.
Therefore,Probability that she catches the bus to and from the shop:
P(A∩B) = 0.4 X 0.7= 0.28
Probability Sue walks at least one way 

Hence, the probability that Sue walks at least one way is 0.72.
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