Answer:
Primul copil are 6 lei, al doilea are 12 lei, al treilea are 27 de lei.
Step-by-step explanation:
Lăsați suma primului copil să fie x.
Lăsați suma al doilea copil să fie y.
Lăsați suma al treilea copil să fie z.
Trei dintre ei au 45 de lei în total.
Aceasta înseamnă că:
x + y + z = 45 ________(1)
Al doilea are de două ori valoarea primului:
y = 2x
Al treilea are cu 15 lei mai mult decât al doilea:
z = 15 + y
=> z = 15 + 2x
Puneți valoarea y și z în (1):
x + 2x + 15 + 2x = 45
5x = 45 - 15 = 30
x = 30 / 5 = 6 lei
=> y = 2 * 6 = 12 lei
=> z = 15 + 12 = 27 lei
Primul copil are 6 lei, al doilea are 12 lei, al treilea are 27 de lei.
Answer:
(1, 8.5 ) and ( - 17, 80.5 )
Step-by-step explanation:
Given the 2 equations
y =
x² + 4x + 4 → (1)
y = - 4x + 12
→ (2)
Substitute (1) into (2), that is
x² + 4x + 4 = - 4x + 12
( multiply through by 2 to clear the fractions )
x² + 8x + 8 = - 8x + 25 ( add 8x to both sides )
x² + 16x + 8 = 25 ( subtract 25 from both sides )
x² + 16x - 17 = 0 ← in standard form
(x + 17)(x - 1) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 17 = 0 ⇒ x = - 17
x - 1 = 0 ⇒ x = 1
Substitute these values into either of the 2 equations and evaluate for y
Substituting into (2 )
x = 1 : y = - 4(1) + 12.5 = - 4 + 12.5 = 8.5 ⇒ (1, 8.5 )
x = - 17 : y = - 4(- 17) + 12.5 = 68 + 12.5 = 80.5 ⇒ (- 17, 80.5 )
Answer:
C. 43
Step-by-step explanation:
Answer:
Question 1. Correct choice A
Question 2 Correct choice A
Step-by-step explanation:
To answer the first question, let's do the following operation, subtract the salary for n years of education with the salary for n-1 years of education:

Where:
represents n years of education
represents n-1 years of education.
Then, solving:
.

Since
is always a unit greater than
, its subtraction is always equal to 1.
This result shows that the increase for an additional year of education is always equal to the value of the slope of the line, that is, $ 125.66. Therefore the correct option for this question is "A".
In cuano to the second question:
The intersection of the line with the y-axis occurs when the value of x is equal to zero, or in this case, when the years in the collage are 0.
This means that when there are no years of education in the collage, the salary is expected to be equal to the value of the intersection of the line with the axis y, that is, equal to 24,600 thousand dollars.
Then the correct option is A.