A discount voucher offering 15% off is used to pay a bill. After using the voucher, the bill is reduced to £36.72. How much was the bill before applying the voucher discount?

We can use the is/of=p/100 method for this problem. Since it's 15% off, this would mean that the bill is 85% of what it was initially. Plug the values into the is/of=p/100 formula.

36.72/x = 85/100

Solve  for x.

x=36.72/0.85

x=43.2

So, the bill was $43.20 before applying the voucher discount of 15% off.

£43.2

Step-by-step explanation:

We minus 15 from 100 to get the percentage represented by 36.72

We are using 100 because it represents the total which is unknown

We cross multiple and get our answer

36.72=85%

X =100%

100×36.72÷85=43.2

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.

graph b

step-by-step explanation:

one solution- graph a (clear intercepting point.)

no solution- graph b (they're parallel, there will never be a point of interception.)

infinite solutions- graph c (all points intercept.)