Answer:
(5, 3 ) and (-
, - 10 )
Step-by-step explanation:
Given the 2 equations
2x - y = 7 → (1)
xy = 15 → (2)
Rearrange (1) expressing y in terms of x , that is
y = 2x - 7 → (3)
Substitute y = 2x - 7 into (2)
x(2x - 7) = 15
2x² - 7x = 15 ( subtract 15 from both sides )
2x² - 7x - 15 = 0 ← in standard form
(x - 5)(2x + 3) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 5 = 0 ⇒ x = 5
2x + 3 = 0 ⇒ 2x = - 3 ⇒ x = - 
Substitute these values into (3) for corresponding values of y
x = 5 : y = 2(5) - 7 = 10 - 7 = 3 ⇒ (5, 3 )
x = -
: y = 2(-
) - 7 = - 3 - 7 = - 10 ⇒ (-
, - 10 )
Answer:
-t
Step-by-step explanation:
Additive inverse of t:
t*-1 = -t
20 = 40e^-0.1446t
e^-0.1446t = 0.5
t = ln 0.5 / -0.1446
t = 4.8 days
Answer:
Find the answers below
Step-by-step explanation:
Using m<X as the reference angle
Opposite YZ = 7
Adjacent XY = 10
Hypotenuse XZ = √149
Using the SOH CAH TOA identity
sinX = opp/hyp
sinX =YZ/XZ
sinX = 7/√149
For cos X
cos X = adj/hyp
cos X =10/√149
Using m<Z as reference angle;
Opposite XY = 10
Adjacent YZ = 7
Hypotenuse XZ = √149
Using the SOH CAH TOA identity
sinZ = opp/hyp
sinZ =10/√149
sinZ = 7/√149
For cos Z
cosZ = 7/√149
-16t² + 180t
-16(2)² + 180(2)
-64 + 360
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