Find the coordinates of the point of intersection of the two lines 2x-7y= 2 and 4x+5y=42

x = 8, y = 2

Step-by-step explanation:

2x - 7y = 2             (1)

4x + 5y = 42          (2)

2x = 2 + 7y                      (1)

2(2 + 7y) + 5y = 42         (2)

4 + 14y + 5y = 42

19y = 38

y = 2

2x = 2 + 7(2) = 16

x = 8

x = 10.1

step-by-step explanation:

all of the angles of a tirangle add up to 180º

180 - 65 = 115 (since we already know the value of one angle)

(2x + 7) + (8x + 7) = 115

(combins like terms) 10x + 14 = 115

(isolate the variable subtract 14 from both sides): 10x = 101

(find the variable divide both sides by 10): x = 101/10

x = 10.1

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)