The average of two numbers is 7, and three times the difference between them is 18. Find the numbers. use the simultaneous equation plz guys

10 & 4

Step-by-step explanation:

Let the numbers are a and b.

Their average = 7

= > ( a + b ) / 2 = 7

= > a + b = 2 * 7 = 14 ...( 1 )

Also,

= > 3 times of difference between a and b = 18

= > 3( a - b ) = 18

= > a - b = 6 ... ( 2 )

adding ( 1 ) & ( 2 ) :

= > ( a + b ) + ( a - b ) = 14 + 6

= > 2a = 20

= > a = 10

Thus,

= > a + b = 14 → 10 + b = 14

= > b = 14 - 10 = 4

3

step-by-step explanation:

divide 13.5 by 9 to get the scale factor. it equals 1.5

2 * 1.5 = 3

region b will make the inequalities y < 2x + 1 and y > -x - 2 true ⇒ answer a

step-by-step explanation:

* lets study the graph and the inequality to solve the question

- the inequality y > -x - 2

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = -2 that means the line intersect the y-axis at point (0 , -2)

∵ the sign of the inequality is >

∴ we shad the part over the line

  region a and b

- the inequality y < 2x + 1

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = 1 that means the line intersect the y-axis at point (0 , 1)

∵ the sign of the inequality is <

∴ we shad the part under the line

  region b and c

∵ the common region between the two lines is region b

∴ region b will make the inequalities y < 2x + 1 and y > -x - 2 true