Solve the system of linear equations using linear combination.

3a + 6b = 45

2a – 2b = –12

which is the solution to the system?

ANSWER

(1,7)

EXPLANATION

The given equations are:

1st: 3a + 6b = 45

and

2nd:2a – 2b = –12

Multiply the second equation by 3,

3rd: 6a – 6b = –36

Add the first and third equations.

6a+3a+6b-6b=45+-36

Simplify,

9a=9

a=1

Put a=1 in the second equation:

2(1) – 2b = –12

-2b=-12-2

-2b=-14

b=7

step-by-step explanation: given equation a = h(b 1+b 2)

also we are given values of a, h and b 1 as :

a = 16, h = 4, and b 1 = 3.

in order to solve it for b 2, we need to plug the given values of   a, h and b 1 .

therefore, plugging values of   a, h and b 1   in given equation, we get

16 = 4( 3 + b 2)

first dividing both sides by 4, we get

4 = 3 + b 2

subtracting 3 from both sides, we get

4 -3 = 3 -3 + b 2

1 = b 2.

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true