Twice the difference of a number x and 3

2(x-9) = 2

Step-by-step explanation:

Difference indicates subtraction:

The difference of a number and

9

is

(

x

−

9

)

Twice the difference means

2

(

x

−

9

)

We know that the answer to this is

2

, so as an equation:

2

(

x

−

9

)

=

2

If you solve it we would have:

x

−

9

=

1

←

÷

2

x

=

1

+

9

x

=

10

The difference between

10

and

9

is

1

and twice

1

is

2

.

The number is correct.

Note that written as:

The difference of twice a number and

9

would have a different expression. This would be

2

x

−

9

equation of a line passing through from 2 points (x1, y1) and (x2,y2) is given as

y = mx + c

as two points are passing through it so it will satisfy the equation. so putting both points in equation

(x1,y1) = (0,3)

y1 = mx1 + c

3 = m×0 + c

c = 3

putting 2nd point (x2,y2) = (7,0)

y2 = mx2 + c

0 = m× 7 + c

c + 7m = 0

putting value of c from above

3 + 7m = 0

7m = -3

m = -3/7

so putting value of m and c in final equation.

y = mx + c

y = (-3/7)x + 3

so option 3 is your answer