Let's suppose the diameter (AB) of the circle is 20 cm and AD is 18 cm. How would we calculate DC? Or for that matter, is it possible to calculate angle CBD or angle CAD?

250

step-by-step explanation:

i have not got your picture clearly so see it once again

if y=4x then you will substitute 4x in for y in the second equation.

8x + 4x = 18 combine like terms

12x = 18 divide by 12 on both sides

x = 18/12 or 3/2

now replace x in the first equation with 3/2 to get

y = 4 3/2

y = 6

the answer is a

(3/2,6)

hope that .

brainliest is always apprectiated

sorry but i cant draw that