2x + 5y= 18 4x + 20y= -36 solve and explain first to get right gets brainliest

because 4x+20y=-36,so ( 4x+20y)/2=2x+10y=-18

(2x+10y)-(2x+5y)=-18-18

5y=-36

then y=-7.2

because 2x=18-5y

so x=(18-5y)/2=(18-5*(-7.2)）/2=27

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -