2/3 is it's simplified form
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
X - (-20) = 5
When you subtract a negative, change it to addition:
X + 20 = 5
Subtract 20 from both sides:
X = -15
Any number that ends with a 0 or a 5 would be a multiple of 5 because as you multipy numbers by 5 you start to see a pattern in the ones place of 5,0,5,0,5,0,5,0,... And so on forever
