Answer:2/3 and 2:3
Explanation
Set h to 640 and solve for t:
640 = -490t^2 + 1120t
Subtract 640 from both sides:
-490t^2 + 1120t - 640 = 0
The formula to solve a quadratic equation is:
x = -b -/+ sqrtroot (b^2-4ac)/(2a) where a = -490, b = 1120 and c = -640
Solve:
x = -1120 -/+ sqrtroot (1120^2-4(-490)(-640) )/ 2(-490)
x = 8/7 = 1.1428 = 1.14
Time was 1.14 seconds
Answer:
Step-by-step explanation:
Using a system of equations, it is found that Gina got 22 questions correct in the test.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, the variables are:
- Variable x: Number of questions she got correct.
- Variable y: Number of questions she got wrong.
The test has 30 questions, hence:
x + y = 30 -> y = 30 - x.
She scored 152 points, hence, considering the value of each question:
8x - 3y = 152.
Since y = 30 - x:
8x - 3(30 - x) = 152
11x = 242
x = 242/11
x = 22
Gina got 22 questions correct in the test.
More can be learned about a system of equations at brainly.com/question/24342899
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