In the united states, the average public school teacher currently earns an annual salary near $55,202. reported national average salaries for the last six decades are listed below.

year national average
teachers’ salary
1960 $4,995
1970 $8,626
1980 $15,970
1990 $31,367
2000 $41,807
2010 $55,202
estimate the increase in the national average teachers’ salary over the span of the six decades, 1960 – 2010.

$4,000
$8,000
$15,000
$50,000

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

27/4x^6 y^8

step-by-step explanation:

4(3x^2y^4)^3 (2x^3y^5)^4

=

108x^6 y^12 /16x^12 y^20

=

108 /16x^6 y^8

=

27 /4x^6 y^8

can someone me: the midsegment through the legs of an isosceles triangle is 4 in. find the sides of the triangle if its perimeter is 20 in. ,   and point g is the centroid of the right △abc with hypotenuse ab=18 in. find cg.