Solve systems using Elimination

y = 1.5, x =

Step-by-step explanation:

The given simultaneous equation system is;

-1 - 2·y = -4...(1)

13·x + 2·y = 28...(2)

By elimination method, we have;

From equation (1);

-1 - 2·y = -4

2·y = 4 - 1 = 3

y = 3/2 = 1.5

y = 1.5

We eliminate 'y' from equation (2) by replacing the value of 'y' with 1.5 as follows;

13·x + 2·y = 28

y = 1.5

∴ 13·x + 2 × 1.5 = 28

13·x = 28 - 3 = 25

x = 25/13 = =

x =

answer:

payment just for service  

→

$

87.12

payment for service including tax

→

$

94.09

explanation:

service only with 20% tip  

→

$

72.6

(

1

+

20

100

)

=

$

87.12

in the opening of the question the word 'service' is associated only with the pretax value.

the closing part of the question asks: how much did she pay for the  

service

−−−−−−  

so technically the answer is  

→

$

72.6

(

1

+

20

100

)

=

$

87.12

however, the intention of the question provider may have been that your answer is to be  

$

87.12

(

1

+

8

100

)

=

$

94.09

to 2 decimal places.

'

payment just for service  

→

$

87.12

payment for service including tax

→

$

94.09

tony b

mar 21, 2017

answer:

trying to explain it another way

explanation:

service charge  

.

→

$

72.60

20% tip  

20

100

×

$

72.60

=

$

14.52

−−−−−−  

←

add

$

87.12

tax  

8

100

×

$

87.12

=

$

6.97

−−−−−  

←

add

$

94.09

related questions

many reason,

step-by-step explanation: