If x = 4 and y = 7, evaluate the - following expression: 20 +2(3y - 4x)

110

Step-by-step explanation:

Substitute x = 4 and y = 7

20 + 2 (3y - 4x)

= 20 + 2 [(3 x 7) - (4 x 4)]

= 20 + 2 (21 - 16)

= 20 + 2 (5)

= 22 (5)

= 110

30 (always use .P.E.M.D.A.S.)

Step-by-step explanation:

20+2(3y-4x)

20+2(21-16)

20+2(5)

20+10

30

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.