Y *x =20
y +x =9
rewrite 1st eq. as y = 20/x
subsituute that into 2nd eq.
20/x +x =9
multiply each term by X
20 +x^2 = 9x
subtract 9x from each side:
x^2 - 9x +20 = 0
now factor:
(x-5) (x-4) = 0
solve for x
5-5 = 0
4-4 = 0
so X can be 4 or 5
replace x into equations and solve for Y
so when X = 4, Y = 5
When X = 5, Y = 4
x= 5,4
y = 4,5
Answer:
Jessica worked 13.5 hours at job A
Step-by-step explanation:
Answer:
C. y = ⁵/2x - 5
Step-by-step explanation:
The linear equation representing the information on the table can be expressed in the slope-intercept form as y = mx + b, where,
m = slope = change in y/change in x
b = y-intercept/initial value = the value of y when x is zero
✔️Find m using two pairs given, say (0, -5) and (2, 0):
slope (m) = (0 - (-5))/(2 - 0) = 5/2
m = ⁵/2
✔️Find b:
when x = 0, y = -5. Therefore, y-intercept, b, is -5
b = -5
✔️To write the equation, substitute m = ⁵/2 and b = -5 into y = mx + b
Thus:
y = ⁵/2x + (-5)
y = ⁵/2x - 5
X + 2y - 6 = z..........x + 2y - z = 6
3y - 2z = 7
4 + 3x = 2y - 5z.....3x - 2y + 5z = -4
x + 2y - z = 6.....multiply by -3
3x - 2y + 5z = -4
---------------------
-3x - 6y + 3z = -18 (result of multiplying by -3)
3x - 2y + 5z = -4
--------------------add
-8y + 8z = - 22
-8y + 8z = -22
3y - 2z = 7 .....multiply by 4
----------------
-8y + 8z = -22
12y - 8z = 28 (result of multiplying by 4)
----------------add
4y = 6
y = 6/4 reduces to 3/2
-8y + 8z = -22
-8(3/2) + 8z = -22
-12 + 8z = -22
8z = -22 + 12
8z = -10
z = -10/8 reduces to -5/4
x + 2y - 6 = z
x + 2(3/2) - 6 = -5/4
x + 3 - 6 = -5/4
x - 3 = -5/4
x = -5/4 + 3
x = -5/4 + 12/4
x = 7/4
solution is (7/4, 3/2, -5/4).....x = 7/4, y = 3/2, and z = -5/4