Plz help me this is 7th grade math

x=40

Step-by-step explanation:

so the angle opposite the 20º angle must also be 20º

this means that because 20º and 2 2x's are all on one straight line they must add up to 180

so 180=20+2*2x

    160=4x

    x=40

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116

i agree because i see the other persons thinking is clear