Answer:
value of a.b = -4
Step-by-step explanation:
We need to find a.b
a= 4i-4j
b = 4i+5j
We know that i.i =1, j.j=1, i.j =0 and j.i=0
a.b = (4i-4j).(4i+5j)
a.b = 4i(4i+5j)-4j(4i+5j)
a.b = 16i.i +20i.j-16j.i-20j.j
a.b = 16(1) +20(0)-16(0)-20(1)
a.b = 16 +0-0-20
a.b = 16-20
a.b =-4
So, value of a.b = -4
Answer:
all students on the track-and-field team
Step-by-step explanation:
if the coach wants to find out if they prefer track or field he/she has to ask the people who are experiencing it right now and tell him or her if they prefer this or not
7/8x²-3/4x - 5/8x²-1/4x+2
x²/4-x+2
Answer:
y = -75
Step-by-step explanation:
Simplify both sides of equation
1/5y = -15
multiply both side by 5
1/5y * 5 = -15 * 5
y = -75
For perimeter you just add the sides up, so 15+12+9 which = 36