Question

A certain keyboard has 5 more than twice as many keys across as it does vertically. The special keyboard has a total of 168 keys. ((((((Find the amount of keys positioned vertically and across)))))

Answer 1

168=(2a+5)??????????

Answer 2

168=.5(a)(2a+5) ???????

Answer 3

let x = # of keys across and y = # of keys vertically

Answer 4

ok

Answer 5

"A certain keyboard has 5 more than twice as many keys across as it does vertically"

that all means

x = 2y + 5

Answer 6

The special keyboard has a total of 168 keys

tells us that

x*y = 168

Answer 7

Multiply vertical with across = 168!
Gte quadratic equation solve it, then get the answer!

Answer 8

x*y = 168

(2y + 5)*y = 168 ... plug in x = 2y + 5

2y^2 + 5y = 168

2y^2 + 5y - 168 = 0

I'll let you finish

Answer 9

ummmm

Answer 10

so we are = 0 right now

Answer 11

you now have to solve 2y^2 + 5y - 168 = 0 for y

Answer 12

use the quadratic formula

Answer 13

8??

Answer 14

good y = 8, now use this to find x

Answer 15

did you get across = 21
vertical = 8
????????

Answer 16

yes I did

Answer 17

great

Answer 18

notice how 21*8 = 168

Answer 19

bam