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Pythagoras: If you have a right angled triangle PQR, and length PQ=5cm, length QR=8cm (which is the longest length), then calculate length PR to two decimal places.

Pythagoras' theorem is: a^2+b^2=c^2 (a=short side, b=short side, c=longest side/hypotenuse, ^=squared). Now applying that to this question would mean that a=PQ, b=PR and c=QR. So we can use the figures given...
PS
Answered by Pree S. • Maths tutor
12547 Views

3 postitive whole numbers have a mean of 6. What is the greatest possible range of the numbers?

15: (x+y+z)/3 = 6 so, x+y+z = 18.Range = highest number - lowest number. For the max range, at least 1 of the numbers must be 1. 1,1,16. 16-1 = 15
JW
Answered by Jade W. • Maths tutor
7645 Views

X^2+4x-21=0 Solve for x

Quadractics factorise into double brackets like (x-a)(x-b). We ave to find the facors of -21 which add to make +4. 7 and -3 suffice. (x-3)(x+7) Then x will be equal to 3 and -7 for the equation.
JC
Answered by James C. • Maths tutor
5414 Views

Solve this pair of simultaneous equations: 3x + y= 7 and 3x - y = 5

Step 1: Start off by labeling the 2 equations. 3 x + y = 7 will be equation 1. 3 x - y = 5 will be equation 2. Step 2: rearrange equation 1 to make y the subject. 3 x + y = 7 ---> y = 7 - 3 x (here 3 x is...
AG
Answered by Anna G. • Maths tutor
15834 Views

Solve the simultaneous equations 2a + b =4 and 5a – 3b = -1

When you solve normal equations like 4x-2=7, there is one equation and one unknown value. This case is no different: in order to solve these equations, you need to create one equation with one unknown. We st...
MM
Answered by Molly M. • Maths tutor
15116 Views