Respuesta :

Saumie
Because 45 is half of 90, 5x=90. 5 times 18 is 90 so x is 18.

Answer:

9

Step-by-step explanation:

45+90= 135

180-135= 45

180 beacuse angles in a straight line add up to 180°

45 ÷ 5 beacause 5x means 5 × x

so 45 ÷ 5 = 9

plz mark brainliest