To eliminate the y-terms and solve for x in the fewest steps, by which constants should the equations be multiplied?

first equation: 5x − 4y = 28

second equation: 3x - 9y = 30

the first equation should be multiplied by 3 and the second equation by 5.
the first equation should be multiplied by 3 and the second equation by −5.
the first equation should be multiplied by 9 and the second equation by 4.
the first equation should be multiplied by 9 and the second equation by −4.

(2x + 16) + (x) = 180

step-by-step explanation:

given,

abcd is a quadrilateral inscribed in a circle

angle a is labeled x plus 16, (x + 16)

angle b is labeled x degrees, (x)

angle c is labeled 6x minus 4, (6x – 4)

angle d is labeled 2x plus 16, (2x + 16)

what equation can be used to solve for angle b?

we know that the sum of the opposite angles of a simple quadrilateral inscribed in a circle is 180 degrees.

angle b is opposite angle d

therefore, angle b + angle d = 180

(x) + (2x + 16) = 180 

same as (2x + 16) + (x) = 180