Question

if x+3y=10 and xy=5 then x²+ 9y= ?​

Answer 1

Step-by-step explanation:

x+3y=10. (1)

xy= 5

x= 5/y (2)

put value of x in (1)

5/y+3y=10

5+3y²/y=10

5+3y²=10y

3y²-10y+5. ( solve it )

the you find

x= 5/3 ,-5

put value of x in (2)

then you find value of y = 3 ,-1

now we have x = 5/3,-5 & y= 3,-1

put value of x&y in x²+9y

after solution we find

x²+9y = -218/9 & 34