Question

I need help on doing this

Answer 1

Answer:

#5A=6

5B=4

Step-by-step explanation:

Answer 2

Answer:

5a) x=40   using the formulae for perimeter of a rectangle p=2(l+b)

120=2(l+20) factor out and you have 120=2l+40   make L subject of formulae then you have 2L=120-40   so L=80/2    L=40cm.

(5b) use the same procedure p=2(l+b)   then L=250m.

6a) since both area and perimeter are give then using p=2(l+b),  20=2(L+B)  so (L+b)=20/2    therefore (L+b)=10  

Now introduce the formular for area which is A=L*B   24=L*B     then making L sub of formular L=24/B    substitute into (L+B)=10  then u have 24/B +B =10 find LCM  you then have 24+B^2=10B   this becomes a quadratic equation  B^2 -10B +24 =0 solve and  you have B=4 or 6.   Substitute into (L+B)=10 to find L.  L= 4 or 6

6b) use the same procedure as 6a.

L=2 or 12 and W =12 or 2