R + b = 49
b = 6r
r + 6r = 49
7r = 49
r = 49/7
r = 7 <== he has 7 red beads
b = 6(7)
b = 42 <== he has 42 blue beads
18 students scored 80%
22 students scored 70%
((18 × .8) + (22 × .7)) ÷ .4
(14.4 + 15.4) ÷ .4
(29.8) ÷ .4
74.5
The average score of the whole class was 74.5
Answer: f(x) = 2x - 3
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We're given f(-1) = -5 and f(5) = 7
This means we know the two points (-1,-5) and (5,7) are on the line.
Find the slope
m = (y2-y1)/(x2-x1)
m = (7-(-5))/(5-(-1))
m = (7+5)/(5+1)
m = 12/6
m = 2
The slope is 2.
Use this along with (x1,y1) to find the equation. We'll use point slope form
y - y1 = m(x - x1)
y - (-5) = 2(x - (-1))
y + 5 = 2(x + 1)
y = 2x + 2 - 5
y = 2x - 3
f(x) = 2x - 3
Answer:
(0, - 3) and (4, 5)
Step-by-step explanation:
Given the 2 equations
y = x² - 2x - 3 → (1)
y = 2x - 3 → (2)
Substitute y = x² - 2x - 3 into (2)
x² - 2x - 3 = 2x - 3 ← subtract 2x - 3 from both sides
x² - 4x = 0 ← in standard form
x(x - 4) = 0 ← in factored form
Equate each factor to zero and solve for x
x = 0
x - 4 = 0 ⇒ x = 4
Substitute these values into (2) for corresponding values of y
x = 0 → y = 2(0) - 3 = 0 - 3 = - 3 ⇒ (0, - 3 )
x = 4 → y = 2(4) - 3 = 8 - 3 = 5 ⇒ (4, 5 )