Solve using the substitution method. 3x +2y= 19 xy= 15​

when x = 3 1/3, y = 4.5

or

when x =3 , y = 5

Step-by-step explanation:

Here, we want to solve using substitution

xy = 15

let x = 15/y

Put this into the first equation;

3(15/y) + 2y = 19

45/y + 2y = 19

Multiply through by y

45 + 2y^2 = 19y

2y^2 -19y + 45 = 0

2y^2 - 10y - 9y + 45 = 0

2y(y-5) -9(y-5) = 0

(2y-9)(y-5) = 0

2y-9 = 0

or y-5 = 0

2y = 9 or y = 5

y = 9/2 or y = 5

y = 4.5 or y = 5

Recall;

x = 15/y

x = 15/4.5 or x = 15/5

x = 3 1/3 or x = 3

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !

if a = 1,   and b = 2, then the answer is 47.99999999. if you round that to the nearest whole number, the answer is 48.