4.
solve the shape equation puzzle:
a+ a+ a+ b+ b=20
b+ a+ a=13

3A+2B=20

2A+B=13 ➡×(-2)➡-4A-2B=-26

3A+2B-4A-2B=20-26

-A=-6 ➡A=6

2(6)+B=13➡B=1

A = 6, B = 1.

Step-by-step explanation:

3A + 2B = 20

2A + B = 13          Multiply this by -2:

-4A - 2B = -26     Add this equation to the first equation:

-A = -6

A = 6.

and from the second equation:

2(6) + B = 13

B = 13 - 12 = 1.

coins of silver or gold

step-by-step explanation:

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %