Answer:
3x² + 3x - 36=
(3x+12)(x-3)
x² - 3x - 28=
(x+4)(x-7)
Step-by-step explanation:
For both equations use the method called the "Cross Method". It is useful for these type of factorisation questions called "Trinomials".
For more info on the cross method.
Here it is:
https://www.mathsteacher.com.au/year10/ch10_factorisation/05_cross_mult_method/cross.htm
Hope you enjoyed :D
Imposible triangle, lagest side must be > sum other sides.
Answer:


Since the calculated values is lower than the critical value we have enough evidence to reject the null hypothesis at the significance level of 2.5% and we can say that the true mean is lower than 36 years old
Step-by-step explanation:
Data given
represent the sample mean
represent the sample standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
t would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
System of hypothesis
We need to conduct a hypothesis in order to check if the true mean is less than 36 years old, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
The statistic is given by:
(1)
And replacing we got:
Now we can calculate the critical value but first we need to find the degreed of freedom:

So we need to find a critical value in the t distribution with df =21 who accumulates 0.025 of the area in the left and we got:

Since the calculated values is lower than the critical value we have enough evidence to reject the null hypothesis at the significance level of 2.5% and we can say that the true mean is lower than 36 years old
Area of a triangle: (b*h) /2
So :
(14,5 * 10.5) /2
=152,25 /2
= 76.125
Y intercept = 7/-2 or -3.5