Help math question 1 ,2 ,3 grade 12

Answers:

1.

a. 20%

60/300 × 100/100

= ( 60 × 100 / 300 ) × 1/100 = 20/100

Calculator: 60 ÷ 300 × 100

b. 90%

270/300 × 100/100

270/300 × 100/100= ( 270 × 100 / 300 ) × 1/100 = 90/100

Calculator: 270 ÷ 300 × 100

c. 58.33%

175/300 × 100/100

100/100= ( 175 × 100 / 300 ) × 1/100 = 58.33/100

Calculator: 175 ÷ 300 × 100

2.

a. 35 Students

Calculator: 10 × 350 / 100

b. 93

Calculator: 10 × 930 / 100

c. 118

Calculator: 10 × 1180 / 100

d. 1036

Calculator: 10 × 10,360 / 100

3.

a. 11.1 (Repeated)

Calculator: 50 / 450 × 100%

b. 6.67 (6 Repeated)

Calculator: 50 / 750 × 100%

c. 4.167 (6 Repeated)

Calculator: 50 / 1200 × 100%

Hopefully this helps:)

answer:

c 60% on edg

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12