There are 20 students in the class.
Two ratios that are equal to 7:6 are 14:12 and 21:18, as they are the same, but 7 and 6 are multiplied by the same number (2 in the first, and 3 in the second.)
Answer:
1..JANE FISH FIRST.
2..BEN WAS LAST.
3..20 MIN AHEAD OF RITA
4..BEN WAS 25 MIN BEHIND ALL AND 5 MIN BEHIND RITA
5..9.45 IS THE AVERAGE TIME OF 3 STUDENTS
Step-by-step explanation:
<h3>MARK AS BRAINLIAST</h3>
Answer:
115.24
Step-by-step explanation:
15.35*4.25=65.2375
65.2375+50=115.2375
115.2375 ≈ 115.24
Answer:
x = -2, y = -4
coordinate: (-2, -4)
Step-by-step explanation:
Given system of equations:
a) 4x - 7y = 20
b) x - 3y = 10
1. Make x the subject in the <em>second</em> equation:
⇒ x - 3y = 10 [add 3y to both sides]
⇒ x - 3y + 3y = 10 + 3y
⇒ x = 3y + 10
2. Substitute the given value of x into <em>first</em> equation:
⇒ 4x - 7y = 20
⇒ 4(3y + 10) - 7y = 20 [distribute 4 through the parentheses]
⇒12y + 40 - 7y = 20 [combine like terms]
⇒ 5y + 40 = 20 [subtract 40 from both sides]
⇒ 5y - 40 - 40 = 20 - 40
⇒ 5y = -20 [divide both sides by 5]
⇒ 5y ÷ 5 = -20 ÷ 5
⇒ y = -4
3. Find the value of x by substituting the given value of y into x = 3y + 10:
⇒ x = 3y + 10
⇒ x = 3(-4) + 10 [multiply]
⇒ x = -12 + 10 [add]
⇒ x = -2
4. Check your work:
<em>a) 4x - 7y = 20</em>
⇒ 4(-2) - 7(-4) = 20
⇒ -8 + 28 = 20
⇒ 20 = 20 ✔
<em>b) x - 3y = 10</em>
⇒ -2 - 3(-4) = 10
⇒ -2 + 12 = 10
⇒ 10 = 10 ✔
This system of equations has a solution at (-2, -4).
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