Let,
x = number of texts Leila sent
y = number of texts Abdul sent
z = number of texts Deon sent
Let's generate equations based on the given relationships.
a.) Abdul sent 3times as many messages as Deon.
[tex]\text{ y = 3z}[/tex]b.) Leila sent 9 more messages than Deon.
[tex]\text{ x = z + 9}[/tex]c.) Leila, Abdul and Deon sent a total of 99 text messages during the weekend.
[tex]\text{ x + y + z = 99}[/tex]Step 1: Let's determine the number of texts that Deon sent.
[tex]\text{ x + y + z = 99}[/tex][tex]\text{ x + (3z) + (z + 9) = 99}[/tex][tex]\text{ x + 3z + z + 9 = 99}[/tex][tex]\text{ 5z + 9 = 99}[/tex][tex]\text{ 5z = 99 - 9}[/tex][tex]\text{ 5z = 90}[/tex][tex]\text{ }\frac{\text{5z}}{\text{ 5}}\text{ = }\frac{\text{90}}{\text{ 5}}[/tex][tex]\text{ z = 18 = 18 text messages}[/tex]Therefore, Deon sent 18 text messages.
For Abdul:
y = 3z
y = 3(18)
y = 54
Therefore, Abdul sent 54 text messages.
For Leila:
x = z + 9
x = 18 + 9
x = 27
Therefore, Leila sent 27 text messages.