Answer:
11.20
Step-by-step explanation:
Multiply both equations by 100:
19.99=1999
8.79=879
1999-879=1120
Divide by 100:
1120/100=11.20 saved ................
Answer:
£0.50
Step-by-step explanation:
t = one cup of tea
c = one piece of cake
t + c = £1.10
2t + c = £1.70
the cost increases by £0.60 (£1.70 - £1.10) when you order one more cup of tea which means that one cup of tea costs £0.60
substitute £0.60 into t + c = £1.10
£0.60 + c = £1.10
rearrange to get c = £1.10 - £0.60 = £0.50
so one piece of cake costs £0.50
Firstly, you know you have 27 (35/100)
Make this an improper fraction. 2735/100
Simplify this as much as you can. 547/20
Find how many times 20 will go into 540, and use the 7/20 as the fraction part of your mixed number.
Now, make as many whole as you can and states your remaining. 27 7/20
3x - 5y = 18 over
-10x + 5y = 10
Add them because the 5y's have the right symbols for us to add
-7x = 28
Divide
x = -4
Now you can plug in -4 for x in one equation, I would use the first equation!
3(-4) - 5y = 18
-12 - 5y = 18
Add 12
-5y = 30
Divide
y = -6
Your solutions are going to be:
x = -4
y = -6
To check your work plug x and y into one equation:
3(-4) - 5(-6) = 18
-12 + 30 = 18
18 = 18
Since 18 does equal 18 you know that your solution's work!
