(x+10)°+(2x+20)°=180°. For what value of X is the quadrilateral a parallelogram?

X = 50

Step-by-step explanation: We shall first solve for X in the algebraic expression as follows ;

(X + 10) + (2X + 20) = 180

By removing brackets and collecting like terms we now have

X + 2X + 10 + 20 = 180

3X + 30 = 180

Subtract 30 from both sides of the equation

3X = 150

X = 50

If X has been identified as equal to 50, then the two angles given shall be

Angle 1 = X + 10

Angle 1 = 50 + 10

Angle 1 = 60

Also

Angle 2= 2X + 20

Angle 2 = 2(50) + 20

Angle 2 = 100 + 20

Angle 2 = 120

One of the properties of a parallelogram is, “Opposite angles are congruent.”

The other two angles would also measure 60 and 120, and the sum of all the interior angles shall be;

60 + 120 + 60 + 120 = 360

360 = 360.

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